If you try to run two SQL statements on one connection, you often see this error message:

"HY000 [Microsoft][SQL Server Native Client 11.0]Connection is busy with results for another command"

We regularly see the problem with Microsoft SQL Server, but it also happens with Sybase ASE and others.

To solve you can set the option "SQL_ATTR_CURSOR_TYPE" with the value "SQL_CURSOR_DYNAMIC" to get a server side cursor. This will tell the connection to use a dynamic cursor and you can have several of those.
In Xojo: